A hard disk drive (HDD) includes a magnetic disk drive and a magnetic head in which an element portion including a reproducing element and a recording element is attached to a slider. The element portion can reproduce and/or record data in a state wherein the element flies over a magnetic disk. In such a HDD, it is required to adjust the height (hereinafter, referred to as a flying height of the element) of the element (hereinafter, referred to as a fly element) of the magnetic head in a flying state from the magnetic disk to prevent the fly element from contacting the magnetic disk.
A coil can be employed in the fly element to generate heat by iron loss or copper loss. For example, when a current is applied to the coil, the fly element heats up and expands. Proper adjustment of the temperature of the fly element can prevent the fly element from contacting the magnetic disk.